This invention relates to a method of analyzing a composition of an optical fiber base material to be measured by nondestructive means utilizing radioactive rays.
When the ratio of elements contained in a substance which includes a plurality of elements and the absolute amounts of the elements are obtained by nondestructive means in the substance, a method of analyzing the substance by the steps of irradiating a plurality of monochromatic X-rays to the substance, and measuring the intensities of the transmitted X-rays by a predetermined detecting system is employed.
In addition, a detector having semiconductor elements of Ge or Si is generally used as a detecting system for accurately analyzing the substance.
In the above-mentioned method by the X-rays, the energy of the X-rays is initially determined. Thus, the energy of the generated X-rays cannot be freely varied, and the thickness of the substance to be measured and the accurate analysis responsive to the constituent elements cannot be determined. Furthermore, the detecting system generally employs a detector made of semiconductor elements of Ge and the like, but the Ge detector is expensive, and must be used while cooling with liquefied nitrogen. Thus, the maintenance and the management of the system have difficulties.
On the other hand, in a semiconductor detector mode of Si, the resolution of the energy is excellent, but this is also expensive and must be cooled by liquefied nitrogen. Thus, this detector cannot be conveniently used.